Molecular cloning of human homolog of yeast GAA1 which is required for attachment of glycosylphosphatidylinositols to proteins.
Anchoring proteins to cell surface membranes by glycosylphosphatidylinositols (GPIs) is important. We have isolated a component of the putative transamidase machinery, hGaa1p (human GPI anchor attachment protein). hGAA1 cDNA is approximately 2 kb in length and codes 621 amino acids. The amino acid sequence of hGaa1p is 25%, identical and 57% homologous to that of yeast Gaa1p. Moreover, Kite-Dolittle hydrophobicity plots of both proteins show marked similarity. hGAA1 gene is expressed ubiquitously and mRNA levels are higher in the undifferentiated state. Overexpression of antisense hGAA1 in human K562 cells significantly reduced the production of a reporter GPI-anchored protein.
Hiroi
Y
Y
Department of Medicine III, University of Tokyo School of Medicine, Japan.
Komuro
I
I
Chen
R
R
Hosoda
T
T
Mizuno
T
T
Kudoh
S
S
Georgescu
S P
SP
Medof
M E
ME
Yazaki
Y
Y
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D019556:COS Cells; D002460:Cell Line; D003001:Cloning, Molecular; D018076:DNA, Complementary; D015870:Gene Expression; D017261:Glycosylphosphatidylinositols / Q000378:metabolism*; D006801:Humans; D008562:Membrane Glycoproteins / Q000096:biosynthesis / Q000235:genetics* / Q000378:metabolism; D051379:Mice; D008969:Molecular Sequence Data; D021382:Protein Sorting Signals; D011506:Proteins / Q000378:metabolism*; D017422:Sequence Analysis, DNA; D017386:Sequence Homology, Amino Acid; D014162:Transfection; D014407:Tumor Cells, Cultured
D018076:DNA, Complementary; C093316:GPAA1 protein, human; D017261:Glycosylphosphatidylinositols; C486253:Gpaa1 protein, mouse; D008562:Membrane Glycoproteins; D021382:Protein Sorting Signals; D011506:Proteins